Methods For Testing For Leakages Inside The Swivel Joint - Komatsu PC20R-8 Shop Manual

TESTING AND ADJUSTMENTS
METHODS FOR TESTING FOR LEAKAGES INSIDE THE
SWIVEL JOINT
H Test conditions:
Engine: at working temperature.
.
. Hydraulic oil: 45 ± 55ëC.
1. Functionality test
1 - When a lower actuator (blade, travel motor, travel
increment) is found to be defective, one of the
possible causes of failure is the swivel joint.
2 - In order to ascertain the cause of the defect it is
sufficient to by-pass the joint by connecting (using
a length of additional tubing) the input and output
tubes of the joint of the line to be checked.
If this corrects the defect, it is certainly due to the
swivel joint.
If the defect persists, it can be ascribed to other
causes, but definitely not to the swivel joint.
2. Looking for a defective seal
These controls are to be carried out only on
those lines subjected to working pressures.
The drainage line is therefore not included in
these tests.
The test method consists of pressurising the line to be
checked and measuring any leakages from the adja-
cent lines according to the following tables:
TABLE A
Symbol Line to be controlled (under pressure)
A Travel motor to the right - Reverse
B Travel motor to the left - Forward
C Travel motor to the right - Forward
D Travel motor to the left - Reverse
E Blade cylinder, head side - Rise
F Blade cylinder base side - Descent
The symbols correspond to the symbols stamped onto the input and output ports of the swivel joint.
20-62
METHODS FOR TESTING FOR LEAKAGES
INSIDE THE SWIVEL JOINT
RKP04820
Adjacent line (possible leakages)
Travel motor to the left - Forward
External leak (visible)
Travel motor to the right - Forward
Travel motor to the right - Reverse
Travel motor to the left - Reverse
Travel motor to the left - Forward
Blade cylinder, head side - Rise
Travel motor to the right - Forward
Blade cylinder base side - Descent
Travel motor to the left - Forward
Descent Passage not used
Blade cylinder, head side - Rise
G Increment of travel speed
F Blade cylinder, base side - Descent
E Blade cylinder, head side - Rise
D Travel motor to the left - Reverse
C Travel motor to the right - Forward
B Travel motor to the left - Forward
A Travel motor to the right - Reverse
PC20R-8 PC27R-8
Sym.
B
Ð
C
A
D
B
E
C
F
D
G
E